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a Sheets-Sheet 1] E. TQSTARR. Chair.

No; 224,489; Pat'ehted Feb. 10, I880.

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Chair.

No: 224,489. Patnted Feb. 10, 1880.

W I IIN'ESSES v l VEJV'TOR 3 SheetL- -Sheet 3.

E. T..STARR.

Chair.

Patented Feb. 10,1880.

No 224,489. j

WITNESSES IJVWENTOR By his flttqrneys I Starr:

HUT-LTHOQRAFHER WSHINGTON D C UNITED STAT S PATENT ()FF-ICE.

ELI T. STARR, OF. PHILADELPHIA, PENNSILVANL d, ASSIGNOR TO SAMUEL S.WHITE, ()F SAME PLACE.

Cl-IAIR. I

SPECIFICATION forming part of Letters Patent No. 224,489, dated February10, 1880. Application filed April 16, 1879; Patented in England, July26, 1879.

To all whom it may concern: f 1

Be it known that I, ELI T. S '1ARR, of Philadelphia, in the State of-Pen11sylvania,have invented certain new and useful Improve- 5 ments inChairs, of which the following is a specification. j 1

My invention relates to ,chairs of the class having a wide range ofadjustment, and more especially designed for the use'of dentists,

1 whereby the patient while in the operatingchair iscompletely under thecontrol of the operator, and may be placed in the various positionsnecessary for the easy, skillful, and expeditious performance of dentaloperations,

the chair being adjustablein its several parts, in order to accommodatepersons of different size and insure their ease and comfort.

I My present invention constitutes an improvement on: the dental chairsshown in reissued Letters Patent No. 8,389, of August 27, 1878; inoriginal Letters Patent No. 187,573,

- of February 20, 1877, and in an application for Letters Patent filedby me November 21, 1878, my said invention also being an improve- 2 5ment upon the vertically and horizontally adjustable rocking back or padshown in reissued Letters Patent No. 8,131,.dated March 19, 1878.

The object of my inventionjs to improve the constructiouof dental chairsby giving the backs thereof, while connected withand supported by thechair-frame, a'widerrangeof adjustment relatively to the chair-seatvthan has heretofore been possible, while rendering the back capable ofbeing firmly locked atany.

3 5 desired point in its range of movement, thus insuring easy,reliable, and comfortable support to the patient in whatever posjtionplacedr My invention consists of certainv new combinations of devices,which are recited at the 40 close of the specification. V I

In the accompanying drawings, which represent all my improvements asembodied in a.

dental chair in the best way nowknown to me, Figure 1 is a view, inelevation, of a com- 5 plete chair with my improvements attached; Fig.2, a view, from the rear, of so much of the.

chair, on an enlarged scale, as is necessary to exhibit my improvementsclearly; Fig. 3,; a

vertical central section therethrough 0nthe? line .3 3 of Fig. 2; Fig.4, a transverse section.

I on the line 4 40f Fig. 3 Fig. 5, a section on the line 5 5 of Fig. 3;Fig. 6, a sectional view on the line 6 6 of Fig. 7, through a modified.form of device ,Fig. 7, a sectional view thereof on the line 7 7 of Fig.8, and Fig.8 a section therethrough on the line 8 8 of Fig. 7.

In Fig.1 I have shown a complete chair, resembling in its generalappearance the pedallever hydrostatic chair shown in my applicationhereinbefore referred to, and it will, consequently, be unnecessary togive a description in detail of the baseA, the plunger or spindle B, thefoot-board or platform 0, the adjustable foot-rest D, the seat andseat-frame E, or the chair-frame proper, F, and especially 6 5 is such adescription unnecessary, as my im- 7 provements are applicable to otherforms of base, &c., than those shown. 7

i The chair-frame F is provided at each side, above and in rear of theseat preferably, with 7 lugs or bearings f f, towhich is pivoted, in

.this instance, a supporting-frame or carrier, .G, which carries theback of the chair. This carrier, byreason of its pivotal connection withthe chair-frame, has the capacity of bea clamping or locking device, I,mounted upon the chair-frame, or a lug or projection, 6,

extending therefrom in this instance. This clamp consists, inltheexample shown, of a bOlQfi, extending through an opening or bearing inthe, lug ev of the seat or chair frame, said bolt being surrounded bysuitable sleeves or washers it" upon each side of the supporting-lug e.The bolt has a transverse opening or socket, 6 at one end, throughwhichthe rod 0 H passes, as well as through a similar opening in the sleeveor washer t", surrounding that end 7 of the bolt, and said bolt is alsoprovided at its opposite endwith screw-threads i for the reception of acrank-handle or clamp-nut, a. 5 By tightening this handle or clamp-nutthe rod isclamped by the bolt and its sleeve 6,

sleeve. The clamping of the rod H necessarily clamps the carrier G, withwhich said rod is connected. By loosening the clamping-handle the rod His left free to move endwise in the lockin g device, to permit thecarrier or support G to be adjusted. Any other suitable clamping device,however, maybe employed for the purpose of lockin g the carrier in itsad usted position.

The carrier or support G consists, preferably, of the skeleton-framecurved as shown in the drawings, and is provided at its upper end withsuitable bearings g g, for the reception of a bolt, rod, or suitabletrunnions j, which forms the pivot or axis of thejoint or connection J,which connects the carrier and the back or pad K, and permits the backto be turned, rocked, or swiveled independently of the adjustment of thecarrier-frame G. This joint or connection is fitted with a clamp, whichhas a hollow flat-sided frame, 1, workin g between the bearin gs or lugsg g around the bolt j, which is locked or keyed from turning in saidlugs. This frame 1 carries at its front end a plate, 2, the two beingfirmly connected together, while held a short distance apart, bysuitable connections or bolts 3 3. The plate 2 fits within alongitudinally-slotted slide, L, which is firmly secured to the back orpad K, or forms part thereof, and which is constructed toslidelongitudinally upon the plate 2. By reason of the connection of theback and carrier by the plate and slide the said pad is supported andallowed to slide up and down, or be adjusted endwise or vertically,relatively to the carrier and to the chair-seat.

Interposed between the slide L and the front end of the frame 1 is afriction plate or block, 4, which is prevented from displacement by thebolts 3 3; and in order that the back may be locked or clamped in anyposition to which it may be adjusted by being slid upon the connectionwith the carrier, or by being inclined or rocked upon its pivot or axis,the clamp frame 1 is provided with clamping-shoes 5 6, as clearly shownin Fig. 3, which are tightened by means of the screw or handle M. Thetightening of the screw M forces the shoe 5 tightly against the bolt j,and, as the frame 1 is moved outward by the tightening of said screw,also draws the shoe 6 firmly against the bolt j and the plate 2 againstthe inside of the slide L, thus clamping said slide L firmly between theplate 2 and the friction block 4, and the frame 1,by its shoe, to thebolt 7', thereby locking the back firmly to the carrier or support inthe desired position.

In Figs. 6, 7, and 8 of the drawings I have shown a modified form ofslide-connection and clamp for the back, which are suflicientlyrepresented in the drawings to render unnecessary a specificdescription, these permitting both the independent vertical or endwiseadjustment of the back and its rocking or tilting relatively to thecarrier or support G, and also enabling the back to be clamped in itsvarious positions. It will thus be seen that the back or pad K has thecapacity of adjustment independently of the carrier or support G-thatis, it may be adjusted vertically or endwise, and rocked, tilted, orvariably inclined independently of said carrier, and then firmly lockedor clamped in its adjusted position. A wide range of movement isconsequently given to the back of the chair, as is obvious, said backbeing capable of adjustment by its support or carrier backward andforward to any desired extent relatively to the seat of the chair,which, together with the capacity for adjustment independently of saidcarrier, insures the ease and comfort of patients of all sizes andenables the operator to place the patient in the position mostconvenient for the easy and skillful performance of the delicate dentaloperations. It will also be noted that if the back-carrier be fixed tothe chair-frame the back may be tilted and moved upward and downwardrelatively to the chairseat by reason of the tilting and slidingconnection between the chair-back and the backcarrier, and that the backwhen so moved may be clamped or locked in its position. It will also benoted that the back may be moved backward and forward relatively to theseat, and be tilted relatively to the backcarrier without being slideither upward or downward, and that the back when thus moved may beclamped or locked in the position to which it is moved.

The back carries a head-rest bar, N, which forms a connection betweensaid. back and a variably-adjustable head-rest, N, (or one having a widerange of adjustment,) the said bar, head-rest, and its clamping oradjusting mechanism 0 being substantially the same as that shown in S.S. Whites Letters Patent No. 187,573, dated February 20, 187 7, and aspatented to me December 28, 1875, as No. 171,589.

I do not wish to be understood as broadly claiming herein thecombination of a chairframe with a back capable of rocking and slidingendwise and adapted to be locked in its adjusted position relatively tothe seat of the chair, as that is not of my invention; nor do I wish tobe understood as claiming herein anything shown in the application of T.J. Garrick, of Baltimore, Maryland, filed January 14,1879. Said Garrickshows, among; other things, a back provided with a slidingand rockingconnection governed by a single clamp-screw, whereby said back ispermitted to slide vertically and to rock or tilt and be firmly securedin its adjusted position.

My invention is limited to the combinations set out in the followingclaims, which embrace as an element the back-carrier, capable of beingadjusted backward and forward relatively to the chair-seat, whichelement is not found in the invention of Mr. Garrick, and is not shownor described by him.

I claim- 1. The combination, substantially as hereinbefore set forth, ofthe chair-frame, the backcarrier, the chair-back, the connection betweenIIO the back-carrier and chair-frame which per: mits the said carrier tobe moved backward and forward relatively to the chair-seat, the pivotalconnectionbetween the chair-back and its carrier which permits the'back'to rock or tilt, and the clamp which looks the back firmly to thecarrier as against its rocking movement.

2. The combination, substantially as hereinbefore set forth, of thechair-frame, the backcarrier, the chair-back, the connection between theback-carrier and chair-frame which permits the said carrier to be movedbackward and forward relatively to the chair-seat, the pivotal andsliding connection between the carrier and back which permits the backto both tilt or rock and slide or be adjusted upward and downwardrelatively to said carrier, and the clamp which locks the back to thecarrier both as against its sliding and rocking:

movements. 7

3. The combination, substantially as hereinbefore set forth, of thechair-frame, the backcarrier pivoted at its lower end 'to theframe so asto rock backward and forward relatively to the seat, the clamp to lockthe carrier to adjustable thereon. I

its adjusted position, the chair-back connected with the upper end ofthe carrier by connectively to the chair-seat, the chair-back, the

pivotal connection between the chair-back and its carrier which permitsthe back to rock or tilt, the clamp to lock the back firmly to thecarrier as against its rocking movement, and the head-rest carried bythe back, so as to partake of its movements while independently Intestimony whereof I have hereunto subscribed my name. a a

' ELI T. STARR.

Witnesses:

CHAS. R. GREEN, .EZEKIEL J. EALER.

